What is a booster fan?

• A. A standby fan with no airflow
• B. An auxiliary fan installed in a way that the total ventilation flow where it is installed passes through it
• C. A fan used to cool equipment
• D. A fan used in surface buildings

Answer: (B)

A booster fan is used to increase the overall air movement in the mine by placing an auxiliary fan in the main ventilation path so that all air flowing through that section passes through it. Because the air must go through the booster, it adds pressure and boosts the total ventilation flow reaching the faces, helping to overcome resistance from long routes, obstructions, and leakage. This is different from a standby fan that’s idle, a fan used merely to cool equipment, or a fan used in surface buildings, which don’t purposefully boost the underground main airflow. So the description that specifies an auxiliary fan installed so the total ventilation flow passes through it best matches how a booster fan works.